Environmental concerns and limited natural resources are highlighting the desire for reduced fuel consumption. One promising avenue toward the reduction of fuel consumption is the use of hybrid powertrains. Many hybrid powertrains utilize regenerative braking to increase the overall efficiency of the system. Regenerative braking recovers kinetic energy from a moving vehicle and utilizes the recovered energy to store electrical potential energy. In presently available hybrid powertrain systems, when a battery to store the energy has reached the currently available storage capacity, the braking capability of the regenerative braking system is reduced. The resulting braking power fluctuation may result in driver dissatisfaction or in a generally lower driver reliance on the regenerative braking system. Therefore, further technological developments are desirable in this area.